U.S. Pat. No. 7,391,862B “COMMUNICATION UNIT” (assignee GN NETCOM A/S) discloses a Bluetooth headset with a foldable microphone arm, where a switch is associated with the microphone arm, so that the headset is powered Off, when the microphone arm is flipped into a compact position, where it is lying along the housing, and powered on, when the microphone arm is flipped into an extended position, where it is ready for use. When such a headset is packaged, it is desire from the seller to present the headset as presentable as possible. Therefore, it is desirable to package a headset of the above type with the microphone arm in extended position, whereby a potential buyer can see how it looks during use through a transparent window of the package. However, if a headset according to U.S. Pat. No. 7,391,862 is packaged this way, the battery will be drained quickly, which is a disadvantage for several reasons. Firstly, it forces the user to recharge the battery before he can use it for the first time. Secondly, the battery may be partly damaged or lose capacity, if it is stored for a long time completely discharged.
A monaural headset is a headset with only one speaker, which is located close to one of the user's ear when the headset is attached to the head of a user. So called “duo headsets” comprise a speaker for both ears and are often preferred in order to improve listening and dampen ambient noise. Monaural headsets are preferred when the user wants to hear ambient sounds and/or a compact headset. Especially Bluetooth headsets used with mobile phones are normally of the monaural type, whereby they are compact and can be carried in a pocket. The attachment means of these Bluetooth headsets are often an ear hook to be located around the outer ear or an ear bud which is inserted into and fixated in the concha. The latter is called “in the ear” headsets, as the earbud is inserted into the outer ear of the user. An example of such a headset is Jabra Extreme. These in the ear headsets may be provided with ear hooks or headbands in order to attach them better to the user's head. When using such a headset the user can hear ambient noise through the ear, which is not used for the headset. Thus, the user is not isolated from the surroundings. However, the noise from the surroundings can make it hard to hear the audio coming from the headset speaker. This is especially the case with so-called “on the ear” headphones, where ambient noise often can enter the ear canal as the earphone does not isolate the ear canal entrance from the surroundings. On-the-ear headsets requires attachment means in the form of an ear hook, ear loop, headband, neck or the like.
U.S. Pat. No. 7,031,460 describes how active noise cancelling works and a telephonic handset employing feed-forward noise cancelling.